Ditching two experimental nuclear reactors set to replace the aging National Research Universal reactor at Chalk River, Ontario cost the Atomic Energy of Canada Limited more than $116 million, according to its yearly financial report. However, the agency says the 53-year-old NRU could last well beyond its 2016 expiration date.

Around $53 million is going to reimburse Ottawa-based Nordion Inc. for enriched uranium fuel at the MAPLE 1 and MAPLE 2 reactors, the abandoned reactors AECL hoped to bring online in 1999 to replace the NRU. The rest of the money is going to put the MAPLE reactors in an extended shutdown state, AHN reports.

The Vancouver Sun reports that because of contractual obligations, the AECL now has nearly 100 pounds of weapons-grade high-enriched uranium under heavy guard. Because of design differences, the fuel cannot be used with the NRU reactor. The company refused to comment on what would become of the stockpile, citing security, legal and commercial concerns, the newspaper said.

However, the AECL said the lifespan of the NRU reactor -- the world's oldest operating reactor -- could extend beyond 2016, the end of its next five-year operating license, which it's expected to acquire next year.

The NRU reactor was shut down for more than a year after a heavy water leak was discovered in May 2009. The 15-month repairs, which cost nearly $72 million, disrupted the world's supply of medical isotopes.